Adjustable work platform for pipe and casing stabbing operations

ABSTRACT

A stabbing board, for a rig and for supporting a worker while stabbing joints of tubular members, comprises a frame member, a platform to support the worker, a carriage, vertical power means for moving the carriage vertically with respect to the frame member, a linkage to connect the platform to the carriage and to facilitate horizontal movement of the platform relative to the carriage and the frame member and horizontal power means for moving the platform horizontally with respect to the frame member. Preferably, the linkage is a scissors linkage.

FIELD OF THE INVENTION

The present invention relates generally to a handling board or platform and, more particularly, to a stabbing board assembly mountable on a well derrick for supporting a worker while stabbing joints of pipe or casing during running operations.

BACKGROUND OF THE INVENTION

It is common practice in the oil and gas well drilling art to provide some form of support or platform for accommodating an operator or worker at a position above the floor of the derrick, particularly during a running of pipe or tubulars into the well, in order to assist in properly axially aligning the tubulars during the stabbing operation. Typically this is accomplished through the use of casing stabbing boards, which are hung or suspended on wirelines held within the derrick or drilling rig.

Additionally, in the prior art, a number of devices have been developed to improve upon such hung or suspended stabbing boards. For example, U.S. Pat. No. 4,326,602 to Bryant, which is herein incorporated by reference in its entirety, teaches a portable stabbing board adapted to be attached to a rig which includes a frame member mountable with the rig and a platform adapted for vertical movement along the frame member for supporting a worker during running operations. However, the stabbing board of Bryant does not provide for any horizontal movement of the platform to allow an operator to be placed in sufficient proximity to the pipe or tubulars during stabbing operations and to easily and quickly allow the platform to move away from the pipe or tubulars when the operator has completed his task of stabbing the tubular.

U.S. Pat. No. 2,425,302 to Calhoun, which is herein incorporated by reference in its entirety, teaches a more permanently mounted stabbing board which can be adjusted in a horizontal manner. However, the stabbing board of Calhoun is designed to be kept or locked in a fixed horizontal relation through the use of bolts (55) positioned through aligned openings (53) in both the telescoping sleeve (42) and hanger rail (40), as well as through the use of a bar (58) the end of which are receivable in eyes (60) and (62). As such, the stabbing board of Calhoun cannot easily and quickly move the platform away from the pipe or tubulars when the operator has completed the stabbing operations so as to reduce the risk of the operator being hit or injured by to the moving blocks or other equipment within the derrick.

Accordingly, there still exists a need to for an improved stabbing board that will provide ease of platform movement in both the horizontal and vertical directions, that is stable and which is simple in design.

SUMMARY OF THE INVENTION

The present invention provides improvements to stabbing boards and stabbing baskets.

In one embodiment, the present invention provides a stabbing board for a rig and for supporting a worker while stabbing joints of tubular members together during running operations, comprising a frame member, a platform to support the worker, a carriage, vertical power means for moving the carriage vertically with respect to the frame member, a linkage to connect the platform to the carriage and to facilitate horizontal movement of the platform relative to the carriage and the frame member and horizontal power means for moving the platform horizontally with respect to the frame member.

In another aspect of the invention the linkage of the stabbing board is a scissors linkage and the vertical power means comprises a leadscrew mounted within the frame member, a motor to drive the leadscrew and a nut mounted on the carriage to receive the leadscrew.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein:

FIG. 1 is a side perspective view of a stabbing board according to a preferred embodiment of the invention, shown with the linkage in an extended state, the platform moved away from the frame member and with the carriage and platform having moved some distance vertically up along the frame member;

FIG. 2 a is a side perspective view of a stabbing board of FIG. 1, also shown with the linkage in an extended state, the platform moved away from the frame member, the carriage and platform having moved some distance vertically up along the frame member and further with a worker being supported by the platform;

FIG. 2 b is a side perspective view of a stabbing board of FIG. 1, now shown with the linkage in a collapsed state, the platform moved adjacent the frame member, the carriage and platform having moved vertically down along the frame member and with a worker being supported by the platform;

FIG. 3 is a side perspective view of the carriage, linkage, platform (showing also the safety barrier assembly) and horizontal power means of the stabbing board of FIG. 1, shown with the linkage in an extended state;

FIG. 4 is a side perspective view of the carriage, linkage, platform and horizontal power means as shown in FIG. 3, but with the safety barrier assembly no longer being shown;

FIG. 5 is a side perspective view of the carriage, linkage, platform and horizontal power means as shown in FIG. 4, but with further components being hidden to more clearly illustrate certain other components thereof;

FIG. 6 is a side perspective view of the frame member, vertical power means and carriage, of the stabbing board of FIG. 1, shown with the carriage having moved some distance vertically up along the frame member;

FIG. 7 is a side perspective view the frame member, vertical power means and carriage as shown in FIG. 6, but with components being hidden to more clearly illustrate certain other components thereof;

FIG. 8 is a side perspective view of the stabbing board of FIG. 1, shown with the carriage at a lower most position along the frame member, with the linkage in a collapsed state, with the platform adjacent the frame member and with the platform floor being pivoted (upwardly) in a stowed position;

FIG. 9 is a side perspective view of the lower portion of the stabbing board as shown in FIG. 8; and

FIG. 10 is another side perspective view of the stabbing board as shown in FIG. 2 a.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description is of a preferred embodiment by way of example only and without limitation to the combination of features necessary for carrying the invention into effect. Reference is to be had to the Figures in which identical reference numbers identify similar components. The drawing figures are not necessarily to scale and certain features are shown in schematic form in the interest of clarity and conciseness.

FIGS. 1-10 illustrate the configuration of a preferred embodiment of the present invention. In this embodiment, stabbing board 10 is adapted to be removably attached to a rig (not shown) from the inside and for supporting a worker W in stabbing joints of tubular members (also not shown) together during running operations.

The stabbing board 10 of this embodiment includes generally a frame member 12, rig attachment means 14 to attach or mount the stabbing board to the inside of a rig, a platform 16 to support the worker W, a carriage 22 to slidably mount the platform 16 to the frame member 12, vertical power means 18 for moving the carriage 22 and platform 16 vertically with respect to the frame member 12, a linkage 30 to interconnect the platform 16 with the carriage 22 and to facilitate horizontal movement of the platform 16 relative to the carriage 22 and frame member 12, and horizontal power means 40 for moving the platform 16 horizontally with respect to the frame member 12. Unless otherwise specified, it is preferred that the components of the invention be made of steel or other suitable high-strength materials capable of taking stresses and strains encumbent upon such a stabbing board 10 during its intended use during stabbing operations.

As is well known and preferred, the drilling rig has a plurality of horizontal girders or braces connecting its legs. Frame member 12 is adapted to be affixed with the rig, along the rig's inside periphery, using one or more of the rig's horizontal girders, in a vertical plane substantially parallel with the tubulars. The frame member 12 includes includes a pair of vertical, substantially parallel channel members 12 a, 12 b. The channel members 12 a, 12 b preferably are of a U-shaped channel having channel troughs 12 a′, 12 b′ formed within the U-shaped channel members with the channel troughs 12 a′, 12 b′ of the channel members 12 a, 12 b facing inwardly with respect to the frame member 12. Top frame member 12 c and bottom frame member 12 d separate and maintain the substantially parallel vertical relationship of the channel members 12 a, 12 b and provide for the upper and lower strength of the frame member 12 of the present invention. A plurality of braces 12 e provide further structural support for the frame member 12 and are mounted therewith adjacent the exterior surface of the vertical channel members 12 a, 12 b and preferably not within the troughs 12 a′, 12 b′ of the channel members 12 a, 12 b. The upper end 12 j of the frame member 12 is formed by the top frame member 12 c and the adjacent portions of channel members 12 a, 12 b while the lower end 12 k of the frame member 12 is formed by bottom frame member 12 d and adjacent channel member 12 a, 12 b, respectively. It is preferred that the frame member 12 be of a rigid construction, as noted above.

The stabbing board 10 of the present invention preferably comprises rig attachment means 14 with the frame member 12 for removably securing the frame member 12 with the inside of a rig. In the preferred embodiment, rig attachment means 14 includes a top support member 24 mounted with the upper end 12 j of the frame member 12. The top support member 24 may also be referred to as girder locking assembly and comprises a pair of top supports 24 a, each substantially alike and having a suitable hook 24 b formed adjacent one end thereof. Preferably, the top support 24 a and hook 24 b are an integral unit. The top support member 24 is adapted to supportably engage the rig for supporting the frame member 12. The top support member 24 is mounted with the rig in such a fashion that the top support 24 a may extend through the rig side with a portion thereof disposed on a girder of the drilling rig. Advantageously, the hook 24 b is useful for engaging the girder of rig during installation procedures and to prevent the stabbing board 10 from falling from the rig during such preliminary placement procedures.

The rig attachment means 14 further comprises bottom locating means designated generally as 34. The bottom locating means 34 comprises at least one arm 34 a adapted to be mounted with the lower end 12 k of the frame member 12. Multiple arms 34 a may be used, if desired. The arms 34 a are preferably pivotally mounted to the lower end 12 k at a pivot points P. More preferably, arms 34 a are slidably mounted, using securable sliding means 34 s, with and along the vertical channel members 12 a, 12 b adjacent the lower end 12 k thereof. This preferred arrangement of the bottom locating means 34 results in substantially universal mounting of the arm 34 a with the frame member 12 such that the arm 34 a may pivot and slide in a vertical plane with respect to the frame member 12.

The bottom locating means 34 further includes a sleeve 34 c slidably mounted with arm 34 a and movable along the length thereof as desired. The sleeve 34 c has projecting plate 34 e depending therefrom. Appropriate securing means 34 d which may include an screwable tee handle or the like threaded through a treadable opening within the sleeve 34 c. As such, the bottom locating means 34 is for locating the lower end 12 k of the frame member 12 an appropriate distance from the rig to insure a substantially vertical disposition of the frame member 12 within the rig. The arm 34 a extends from the frame member 12 through the rig side of the drilling rig for engaging a girder thereof. More particularly, the sleeve 34 c is positioned with the arm 34 a such that the sleeve's plate 34 e engages the girder of the rig and the securing means 34 d secures the sleeve and consequently arm 34 a to the drilling rig upon being suitably disposed against the girder, for ease in quick mounting.

In an alternate embodiment (not shown), the stabbing board 10 is permanently attached to the rig, such as by welding or bolting the frame member 12 directly to the rig.

The stabbing board 10 of the present invention further comprises platform 16 for supporting the worker W during running operations. The platform 16 comprises a floor 16 f affixed to a rear platform support 16 r. Rear platform support 16 r comprises a pair of vertical, substantially parallel platform channel members 16 a, 16 b mounted therewith and extending substantially upwardly from the floor 16 f. Top and bottom support members 16 t, 16 bt separate and maintain the substantially parallel vertical relationship of the platform channel members 16 a, 16 b and provide for the upper and lower strength of the rear platform support 16 r. The platform channel members 16 a, 16 b preferably are of a U-shaped channel having channel troughs 16 a′, 16 b′ formed within the U-shaped channel members with the platform channel troughs 16 a′, 16 b′ of the platform channel members 16 a, 16 b facing inwardly with respect to the rear platform support 16 r.

Preferably, the platform 16 further comprises a safety barrier assembly 17 to form the perimeter of a working cage for the worker W utilizing the stabbing board 10 of the present invention. The safety barrier assembly 17 has appropriate braces such as vertical posts 17 a, 17 b and safety chain 17 c for providing a suitable barrier to safely keep worker W on the stabbing board 10 during running operations. More preferably, the platform floor 16 f further comprises a wire screen or metal grate (not shown) to prevent inadvertent slipping of the worker when standing on the floor 16 f. It is preferred that the rear platform support 16 r is sized such that it is of substantially the same width as the vertical channel members 12 a, 12 b of the frame member 12.

Even more preferably, the platform floor 16 f is pivotally connected to the rear platform support 16 r, using a securable pivot means 50, to enable the platform to be folded up in a substantially vertical position, substantially paralled to the rear platform support 16 r, when the platform 16 is not in use and requires to be stowed (see FIGS. 8 and 9).

The stabbing board 10 of the present invention further comprises carriage 22 for supporting the platform 16 and capable of vertical movement V along the frame member 12. Carriage 22 comprises a pair of vertical, substantially parallel carriage channel members 22 a, 22 b. Top and bottom support members 22 t, 22 bt separate and maintain the substantially parallel vertical relationship of the carriage channel members 22 a, 22 b and provide for the upper and lower strength of the carriage 22. The carriage channel members 22 a, 22 b preferably are of a U-shaped channel having carriage channel troughs 22 a′, 22 b′ formed within the U-shaped channel members with the carriage channel troughs 22 a′, 22 b′ of the carriage channel members 22 a, 22 b facing inwardly with respect to the carriage 22.

Carriage 22 is slidably mounted to the frame member 12 for vertical movement V along said frame member 12. Preferably, carriage 22 is disposed within the channel troughs 12 a′, 12 b′ formed within vertical channel members 12 a, 12 b of the frame member 12. More preferably, a plurality of carriage rollers 22 r are provided to facilitate said slidable vertical movement V of the carriage 22 within the channel troughs 12 a′, 12 b′.

The stabbing board 10 of the present invention further comprises vertical power means 18 to provide motive force for moving the carriage 22 vertically with respect to the frame member 12. Preferably, vertical power means 18 is a leadscrew-based power means, further comprising a leadscrew 18 l (threads not shown) mounted within the frame member 12 in a vertical plane substantially parallel with the frame member, a motor 18 m to drive the leadscrew and a nut 18 n mounted on the carriage 22 to receive and treadably mate with the leadscrew 18 l (leadscrew 18 l otherwise passing through carriage through appropriate sized openings, including openings in top and bottom support members 22 t, 22 bt) and to translate the torque of the leadscrew 18 l into linear vertical motive force on the carriage 22. More preferably, the threads of the leadscrew 18 l and nut 18 n have an Acme profile. Even more preferably the motor 18 m is an air motor or may alternatively be an electric, hydraulic or any other suitable type of motor. The carriage 22 (and the platform 16 mounted thereto) is movable vertically along the frame member 12 upon actuation of the vertical power means 18.

Advantageously, the leadscrew-based power means is self-locking (i.e. when stopped, a linear force on the nut 18 n will not apply a torque to the leadscrew 18 l). More advantageously, the vertical power means 18 is therefore capable of holding vertical loads (such as the carriage 22, platform 16 and any worker W positioned thereon) when the motor 18 m is turned of, thereby providing significant safety advantages over a winch and cable based power means such as that disclosed in U.S. Pat. No. 4,326,602 to Bryant.

The stabbing board 10 of the present invention further comprises a linkage 30 to interconnect the platform 16 with the carriage 22 and to facilitate horizontal movement H of the platform 16 relative to the carriage 22 and the frame member 12. Preferably, the linkage 30 is a scissors linkage 30 s capable of moving in the horizontal plane only and comprising laterally off-set, side-by-side scissor linkages, each scissor linkage having one or more sets of lever arms. In this embodiment, scissors linkage 30 s comprises two pairs of lever arms 31, 31′ and 32, 32′ each mounted scissor fashion, i.e. a pair of level arms pivoting about a pin 30 p in their median part, respectively pivoting with the side edges of the platform 16 and carriage 22.

One of the free ends 31 a, 32 a of each of arms 31, 32 is pivotally mounted about a fixed pin 31 p, 32 p secured to the carriage 22, each to their respective carriage channel members 22 a, 22 b. The other free ends 31 b, 32 b, of each of the pairs of arms 31, 32, each pivot about a roller or slider 31 r, 32 r slidably mounted within their respective platform channel troughs 16 a′, 16 b′ of the platform channel members 16 a, 16 b (see FIG. 3). The other free ends 31 b, 32 b are thereby confined to move in a rectilinear manner, that is, with straight line motion, relative to the platform channel members 16 a, 16 b with which they are associated. Preferably, a pivoting cross-member 33 separates and maintains the substantially parallel relationship of free ends 31 b, 32 b and provide for additional strength of the linkage 30.

One of the free ends 31′a, 32′a of each of arms 31′, 32′ is pivotally mounted about a fixed pin 31′p, 32′p secured to the platform 16, each to their respective platform channel members 16 a, 16 b. The other free ends 31′b, 32′b, of each of the pairs of arms 31′, 32′, each pivot about a roller or slider 31's, 32's slidably mounted within their respective carriage channel troughs 22 a′, 22 b′ of the carriage channel members 22 a, 22 b (see FIG. 4). The other free ends 31′b, 32′b are thereby confined to move in a rectilinear manner, that is, with straight line motion, relative to the carriage channel members 22 a, 22 b with which they are associated. Preferably, a cross-member 34 separates and maintains the substantially parallel relationship of free ends 31′b, 32′b and provide for additional strength of the linkage 30.

The stabbing board 10 of the present invention further comprises horizontal power means 40 to provide motive force for actuating the linkage 30 between an extended state (see FIG. 2 a) and a collapsed state (see FIG. 2 b) and, hence, move the platform 16 horizontally with respect to the frame member 12 and, consequently, towards or away from the well center and any tubular members that may be present there.

Horizontal power means 40 may be a hydraulic ram-based means of conventional design. Preferably, however, horizontal power means 40 is a leadscrew-based power means, further comprising a leadscrew 40 l (threads not shown) mounted within the rear platform support 16 r in a vertical plane substantially parallel with platform channel members 16 a, 16 b, a motor 40 m to drive the leadscrew and a nut 40 n mounted on the rear platform support 16 r to receive and treadably mate with the leadscrew 40 l and to translate the torque of the leadscrew 40 l into actuating force on the linkage 30 to move it between an extended state and a collapsed state. More preferably, the nut 40 n integral with the pivoting cross-member 33 and allows leadscrew 40 l to pass therethrough. Advantageously, pivoting cross-member 33 pivots as scissors linkage actuates about free ends 31 b, 32 b, thereby allowing leadscrew 40 l to remain substantially parallel with platform channel members 16 a, 16 b while also still maintaining the substantially parallel relationship of free ends 31 b, 32 b. Even more preferably, the threads of the leadscrew 40 l and nut 40 n have an Acme profile. Yet even more preferably the motor 40 m is an air motor or may alternatively be an electric, hydraulic or any other suitable type of motor.

During running operations the worker W preferably stands on the floor 16 f of the platform 16 for stabbing the appropriate tubular members during such running operations. Should it be necessary that the platform 16 be raised or lowered, the worker merely actuates the vertical power means 18. In the preferred embodiment, the worker W actuates motor 18 m to turn in the appropriate direction, resulting in either upward or downward vertical movement of the carriage 22, and hence the platform 16, along the frame member 12 as may be required. Should it be necessary that the platform 16 be moved towards or away from the tubular members, the worker W merely actuates the horizontal power means 40. In the preferred embodiment, the worker W actuates motor 40 m to turn in the appropriate direction, resulting in actuating the linkage 30 between an extended state and a collapsed state and, hence, move the platform 16 horizontally with respect to the frame member 12 as may be required.

As will be appreciated, the stabbing board 10 of the present invention enables a worker W to efficiently and safely accomplish the stabbing of joints of tubular members during running operations. Advantageously, by having separate vertical and horizontal power means 18, 40, and by having a scissors linkage 30 s which operates in the horizontal plane only, the stabbing board 10 can efficiently move the worker W closer to, or farther away from, the tubular members during stabbing operations.

More advantageously, a worker W supported by the stabbing board can easily and quickly actuate the horizontal power means only, so as to swiftly move the platform 16 away from the pipe or tubulars when the worker W appears to be at risk of being hit or injured by the moving blocks, tubulars or other equipment within the center of derrick or rig. Such movement along the horizontal plane only is preferably, as compared to say the telescoping, luffing or slewing of a boom (where there is both horizontal and vertical movement), in situations of imminent danger when a worker quickly needs to be moved away from the central axis of the derrick and to a position of safety adjacent the derrick's inside periphery. Thus, the present invention comprehends a stabbing board 10 that is a new and useful concept not heretofore known.

Those of ordinary skill in the art will appreciate that various modifications to the invention as described herein will be possible without falling outside the scope of the invention. 

1. A stabbing board for a rig and for supporting a worker while stabbing joints of tubular members together during running operations, comprising: a frame member; rig attachment means to removably attach the frame member to the rig; a platform to support the worker; a carriage; vertical power means for moving the carriage vertically with respect to the frame member; a linkage to connect the platform to the carriage and to facilitate horizontal movement of the platform relative to the carriage and the frame member; and horizontal power means for moving the platform horizontally with respect to the frame member.
 2. The stabbing board of claim 1 wherein the linkage is a scissors linkage.
 3. The stabbing board of claim 1 wherein the horizontal power means provides motive force for actuating the linkage between an extended state and a collapsed state.
 4. The stabbing board of claim 1 wherein the vertical power means comprises: a leadscrew mounted within the frame member in a vertical plane substantially parallel with said frame member; a motor to drive the leadscrew; and a nut mounted on the carriage to receive the leadscrew.
 5. The stabbing board of claim 2 wherein the vertical power means comprises: a leadscrew mounted within the frame member in a vertical plane substantially parallel with said frame member; a motor to drive the leadscrew; and a nut mounted on the carriage to receive the leadscrew.
 6. A stabbing board for a rig and for supporting a worker while stabbing joints of tubular members together during running operations, comprising: a frame member; a platform to support the worker; a carriage; vertical power means for moving the carriage vertically with respect to the frame member; a linkage to connect the platform to the carriage and to facilitate horizontal movement of the platform relative to the carriage and the frame member; and horizontal power means for moving the platform horizontally with respect to the frame member.
 7. The stabbing board of claim 6 wherein the linkage is a scissors linkage.
 8. The stabbing board of claim 6 wherein the horizontal power means provides motive force for actuating the linkage between an extended state and a collapsed state.
 9. The stabbing board of claim 6 wherein the vertical power means comprises: a leadscrew mounted within the frame member in a vertical plane substantially parallel with said frame member; a motor to drive the leadscrew; and a nut mounted on the carriage to receive the leadscrew.
 10. The stabbing board of claim 7 wherein the vertical power means comprises: a leadscrew mounted within the frame member in a vertical plane substantially parallel with said frame member; a motor to drive the leadscrew; and a nut mounted on the carriage to receive the leadscrew. 